1. Field of the Invention
This invention relates to a color diffusion transfer photographic light-sensitive sheet. More particularly, it relates to a color diffusion transfer silver halide photographic light-sensitive sheet containing a novel dye-providing compound.
2. Description of the Prior Art
In diffusion transfer photography, compounds wherein a dye compound moiety is bound to a diffusibility-controlling moiety are used as dye-providing compounds. The diffusibility-controlling moiety is a moiety which changes the diffusibility of the dye-providing compound as a result of development processing under alkaline conditions. The dye-providing compounds are generally classified into dye-releasing type compounds and dye-immobilizing type compounds according to the function of the diffusibility-controlling moiety. The dye-releasing type dye-providing compounds are originally non-diffusible but as a result of development processing under alkaline conditions, they release a diffusible dye. As the examples of such dye-releasing type dye-providing compounds are dye-releasing redox compounds.
On the other hand, dye-immobilizing type dye-providing compounds are compounds which are originally diffusible (or release a diffusible dye) but which, as a result of development processing, become non-diffusible (or do not release a diffusible dye). Examples of such dye-immobilizing type dye-providing compounds are described in Japanese Patent Application (OPI) Nos. 63618/76 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") and 35533/78.
Japanese Patent Application (OPI) Nos. 115528/75 and 104343/76, U.S. Pat. Nos. 3,928,312, 3,931,144, 3,932,381, 3,942,987, 3,954,476, 3,993,638, 4,076,529 and 4,152,153 and Research Disclosure, Vol. 130, 13024 (published in Feb., 1975) describe color diffusion transfer process for forming color images using dye-releasing redox compounds. The term "dye-releasing redox compounds" refers to compounds wherein a diffusibility-controlling moiety, called a redox mother nucleus, is bound to a dye moiety or a precursor thereof. This redox mother nucleus first immobilizes the redox compound as a function of the ballast group bound thereto but upon oxidation-reduction (redox) reaction under alkaline conditions, the compound cleaves to release a dye moiety-containing compound (dye compound). That is, when a light-sensitive material containing a light-sensitive silver halide emulsion layer associated with this redox compound is imagewise exposed and developed with an alkaline processing solution, this redox compound per se is oxidized in proportion to the amount of developed silver halide and is further cleaved into a compound containing a dye moiety (hereinafter referred to as a dye compound) and a non-diffusible quinone compound. As a result, this dye compound diffuses into an image-receiving layer to provide a transferred image there.
Examples of yellow-dye-releasing redox compounds are described in U.S. Pat. No. 3,928,312, Research Disclosure, 130, 13024 (published in Feb., 1975), etc. However, the stability of the transferred images is insufficient (for example, the light resistance is so poor that the color image suffers serious fading in a bright place), and transfer of the dye moiety is inadequate (i.e., the transfer rate is slow).
Japanese Patent Application (OPI) No. 149328/78 describes azopyrazolone yellow dye-providing compounds containing an --O--R.sup.1 --O--R.sup.2 moiety in the molecule. However, subsequent investigations have shown that the light fastness of the dyes must be improved and when the pH changes, the image hue changes.
Research Disclosure, 16475 (published in Dec., 1977) describes improved yellow dye-providing compounds but the hue of the released dye compound undergoes serious changes depending upon pH.